In the (adorable) post, the couple's daughter, Luna, can be seen patting Teigen's stomach. "Luna, what's in there?" Teigen asked her.

"Baby!" Luna replied.

Teigen and Legend have been open both about their desire to have more kids and their struggle to conceive. The 31-year-old model and cookbook author told InStyle in October that out of the 20 embryos that resulted from her last round of IVF, she was left with only three viable ones. The first ended in a miscarriage; the second resulted in baby Luna. In January, after being criticized for using IVF, Teigen confirmed that baby number two would be a boy.

In March, Teigen penned an article for Glamour, where she revealed that, like many women, she suffered from postpartum depression. She got through the tough time with support from Legend, and in October, revealed that she and Legend were trying for a second child with their remaining embryo.

Congratulations! As for what kind of big sister Luna will be? "I don't know," Teigen told People magazine. "She's very sweet and likes to share, so hopefully that will translate."